/*
 * Copyright (C) 2006 Alexey Proskuryakov <ap@webkit.org>
 * Copyright (C) 2010 Patrick Gansterer <paroga@paroga.com>
 * Copyright (C) 2013, 2016 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#ifndef Base64_h
#define Base64_h

#include "../Vector.h"
#include "CString.h"
#include "WTFString.h"

namespace WTF {

    enum Base64EncodePolicy {
        Base64DoNotInsertLFs,
        Base64InsertLFs,
        Base64URLPolicy // No padding, no LFs.
    };

    enum Base64DecodeOptions {
        Base64Default = 0,
        Base64ValidatePadding = 1 << 0,
        Base64IgnoreSpacesAndNewLines = 1 << 1,
    };

    class SignedOrUnsignedCharVectorAdapter {
    public:
        SignedOrUnsignedCharVectorAdapter(Vector<char> &vector)
                : m_isSigned(true) {
            m_vector.c = &vector;
        }

        SignedOrUnsignedCharVectorAdapter(Vector<uint8_t> &vector)
                : m_isSigned(false) {
            m_vector.u = &vector;
        }

        uint8_t *data() {
            if (m_isSigned)
                return reinterpret_cast<uint8_t *>(m_vector.c->data());
            return m_vector.u->data();
        }

        size_t size() const {
            if (m_isSigned)
                return m_vector.c->size();
            return m_vector.u->size();
        }

        void clear() {
            if (m_isSigned) {
                m_vector.c->clear();
                return;
            }
            m_vector.u->clear();
        }

        void grow(size_t size) {
            if (m_isSigned) {
                m_vector.c->grow(size);
                return;
            }
            m_vector.u->grow(size);
        }

        void shrink(size_t size) {
            if (m_isSigned) {
                m_vector.c->shrink(size);
                return;
            }
            m_vector.u->shrink(size);
        }

        uint8_t &operator[](size_t position) { return data()[position]; }

    private:
        bool m_isSigned;
        union {
            Vector<char> *c;
            Vector<uint8_t> *u;
        } m_vector;
    };

    class ConstSignedOrUnsignedCharVectorAdapter {
    public:
        ConstSignedOrUnsignedCharVectorAdapter(const Vector<char> &vector)
                : m_isSigned(false) {
            m_vector.c = &vector;
        }

        ConstSignedOrUnsignedCharVectorAdapter(const Vector<uint8_t> &vector)
                : m_isSigned(true) {
            m_vector.u = &vector;
        }

        const uint8_t *data() const {
            if (m_isSigned)
                return reinterpret_cast<const uint8_t *>(m_vector.c->data());
            return m_vector.u->data();
        }

        size_t size() const {
            if (m_isSigned)
                return m_vector.c->size();
            return m_vector.u->size();
        }

    private:
        bool m_isSigned;
        union {
            const Vector<char> *c;
            const Vector<uint8_t> *u;
        } m_vector;
    };

    WTF_EXPORT_PRIVATE void base64Encode(const void *, unsigned, Vector<char> &, Base64EncodePolicy = Base64DoNotInsertLFs);

    void base64Encode(ConstSignedOrUnsignedCharVectorAdapter, Vector<char> &, Base64EncodePolicy = Base64DoNotInsertLFs);

    void base64Encode(const CString &, Vector<char> &, Base64EncodePolicy = Base64DoNotInsertLFs);

    WTF_EXPORT_PRIVATE String

    base64Encode(const void *, unsigned, Base64EncodePolicy = Base64DoNotInsertLFs);

    String base64Encode(ConstSignedOrUnsignedCharVectorAdapter, Base64EncodePolicy = Base64DoNotInsertLFs);

    String base64Encode(const CString &, Base64EncodePolicy = Base64DoNotInsertLFs);

    WTF_EXPORT_PRIVATE bool base64Decode(const String &, SignedOrUnsignedCharVectorAdapter, unsigned options = Base64Default);

    WTF_EXPORT_PRIVATE bool base64Decode(const Vector<char> &, SignedOrUnsignedCharVectorAdapter, unsigned options = Base64Default);

    WTF_EXPORT_PRIVATE bool base64Decode(const char *, unsigned, SignedOrUnsignedCharVectorAdapter, unsigned options = Base64Default);

    inline void base64Encode(ConstSignedOrUnsignedCharVectorAdapter in, Vector<char> &out, Base64EncodePolicy policy) {
        base64Encode(in.data(), in.size(), out, policy);
    }

    inline void base64Encode(const CString &in, Vector<char> &out, Base64EncodePolicy policy) {
        base64Encode(in.data(), in.length(), out, policy);
    }

    inline String base64Encode(ConstSignedOrUnsignedCharVectorAdapter in, Base64EncodePolicy policy) {
        return base64Encode(in.data(), in.size(), policy);
    }

    inline String base64Encode(const CString &in, Base64EncodePolicy policy) {
        return base64Encode(in.data(), in.length(), policy);
    }

// ======================================================================================
// All the same functions modified for base64url, as defined in RFC 4648.
// This format uses '-' and '_' instead of '+' and '/' respectively.
// ======================================================================================

    WTF_EXPORT_PRIVATE void base64URLEncode(const void *, unsigned, Vector<char> &);

    void base64URLEncode(ConstSignedOrUnsignedCharVectorAdapter, Vector<char> &);

    void base64URLEncode(const CString &, Vector<char> &);

    WTF_EXPORT_PRIVATE String

    base64URLEncode(const void *, unsigned);

    String base64URLEncode(ConstSignedOrUnsignedCharVectorAdapter);

    String base64URLEncode(const CString &);

    WTF_EXPORT_PRIVATE bool base64URLDecode(const String &, SignedOrUnsignedCharVectorAdapter);

    WTF_EXPORT_PRIVATE bool base64URLDecode(const Vector<char> &, SignedOrUnsignedCharVectorAdapter);

    WTF_EXPORT_PRIVATE bool base64URLDecode(const char *, unsigned, SignedOrUnsignedCharVectorAdapter);

    inline void base64URLEncode(ConstSignedOrUnsignedCharVectorAdapter in, Vector<char> &out) {
        base64URLEncode(in.data(), in.size(), out);
    }

    inline void base64URLEncode(const CString &in, Vector<char> &out) {
        base64URLEncode(in.data(), in.length(), out);
    }

    inline String base64URLEncode(ConstSignedOrUnsignedCharVectorAdapter in) {
        return base64URLEncode(in.data(), in.size());
    }

    inline String base64URLEncode(const CString &in) {
        return base64URLEncode(in.data(), in.length());
    }

} // namespace WTF

using WTF::Base64EncodePolicy;
using WTF::Base64DoNotInsertLFs;
using WTF::Base64InsertLFs;
using WTF::Base64ValidatePadding;
using WTF::Base64IgnoreSpacesAndNewLines;
using WTF::base64Encode;
using WTF::base64Decode;
using WTF::base64URLDecode;

#endif // Base64_h
